Smart cards having a built-in IC are used as banking cards or in terminals of satellite telecommunications systems. In order to read information stored on the IC of these cards, card connectors are known, such as, for example, a chip-card connector described in U.S. Pat. No. 5,334,827. Such a connector 100 shown in FIG. 7 has a set of sensors 104, 104' of identical configuration. At the upper part of the sensor 104, an arm 108 is provided which extends sidewise under a bottom surface of arm 108' of the sensor 104' with which it forms a normally-closed circuit. When a card (not shown) is inserted in slot 106, its front edge pushes upwardly slanted surface 110' of the arm 108' of the sensor 104'. As a result, the engagement between arms 108, 108' is broken, the circuit is open, thereby indicating that the card is fully inserted.
Japanese Patent No. 2,615,161 describes a detecting device comprising two contact blades together forming a normally-closed detecting circuit; one of the blades can move in the direction of the card insertion and the other one is fixed.
Since in the conventional card connector 100, the slanted surface 110' of the arm 108' is pushed upwards by the card, a clockwise torque is applied to arm 108'. When the card is fully inserted, a front edge of the card is located just under a flat section 109' of the arm 108'. However, due to vibration or other mechanical action, the front edge of the card can be displaced under slanted surface 110'. As a result, the spring-loaded action of the arm 108' will push the card in the direction of ejection, that is to the right side of FIG. 7, thus reducing reliability of the electrical connections of the card. If a card is thick, there is a danger that its front edge can engage against end 108'a of the arm 108' and deform it.
In the second example disclosed in the Japanese Patent, pressure from the movable blade is always applied to the inserted card in the direction of ejection which also can adversely affect the reliability of the electrical connections.
The purpose of the present invention is to provide a card connector free of the above-mentioned disadvantages which would include a detecting or sensing unit exerting no force ejecting a card after it has been fully inserted into the connector and providing reliable electrical connections between the card and the connector.
The other purpose of this invention is to provide a card connector that prevents deformation of the detecting unit at the time of card insertion into the connector.